@Octane That's been my assumption, but the cadence of their trailer is that of a new game. They didn't say what it was, that's the problem.

Anyway, I'm looking forward to them destroying Link's playstyle like Breath of the Wild did to Zelda's unique puzzle-y genre. Semi /s, I never got terribly good at his projectile attacks anyway. And it's definitely time for Mario's cape and Fludd to be replaced with a cap toss, roll, or something along those lines.

It'd be nice if more of these legacy characters got revamps. I recognize that now would be an incredibly ironic time to give the Ganondorf character an identity given that he didn't have one in Breath, but I'd still like for him to get his own actual playstyle rather than Captain Falcon's D-tier cousin.

Splatoon was obvious in terms of new characters, but Nintendo doesn't exactly have many obvious examples from recent games. They've more mascots than characters really. And putting Springman in would be kind of strange, because he's already in a Nintendo fighting game and there's no way many of those characters are getting into Smash. It'd be nice if they brought some old standout characters back; Vivian, Midna, someone from Metroid Prime and Luigi's Mansion.

Almost certainly a port due to announcement and release timing, but I imagine it'll be way more "enhanced" than MK8DX.

For starters we already have a new character. MK introduced new characters but they don't affect the core experience as much as in Smash.
Nintendo have the full selection of Wii U and 3DS stages to go back to.
We know there's Breath of the Wild Link - new skin, or will this influence his moveset?
Will Mario have a cappy move?
etc etc.

Plus 2018 is only launch. They can continue to update it post-launch. Even if it is a port, it can evolve into a game completely different from Smash 4.

i'm just gonna call it Smash Bros until nintendo confirmed that it's a port or not.
if it is a port. Please Nitendo included both the 3ds and Wii U version. if it's not than cool.
also press release from Nintendo said.

Nintendo Switch Super Smash Bros. (working title): The Super Smash Bros. series comes to Nintendo Switch in 2018. The teaser trailer featured recognizable faces like Mario, Link and the Inklings from the Splatoon series.

so, take that as you well. but, i don't really care because it's smash. just, as long as it adds new stuff (other then the inkling,)